Merge pull request #2971 from zendesk/grosser/cursor

better ignore cursor movement for less spammy docker builds

app/models/terminal_executor.rb

@@ -15,6 +15,7 @@
 #
 class TerminalExecutor
   SECRET_PREFIX = "secret://"
+  CURSOR = /\e\[\d*[ABCDK]/
 
   attr_reader :pid, :pgid, :output, :timeout
 
@@ -104,13 +105,19 @@ def timeout_execution(time, &block)
   def stream(from:, to:)
     from.each(256) do |chunk|
       chunk.scrub!
-      chunk = chunk.gsub(/\r\e\[\d+[ABCD]\r\n/, "\r") # ignore cursor movement http://ascii-table.com/ansi-escape-sequences.php
+      ignore_cursor_movement!(chunk)
       to.write chunk
     end
   rescue Errno::EIO
     nil # output was closed ... only happens on linux
   end
 
+  # http://ascii-table.com/ansi-escape-sequences.php
+  def ignore_cursor_movement!(chunk)
+    chunk.gsub!(/\r#{CURSOR}\r\n/, "\r")
+    chunk.gsub!(CURSOR, "")
+  end
+
   def script(commands)
     commands.map! do |c|
       if @verbose

test/models/terminal_executor_test.rb

@@ -129,8 +129,8 @@
     end
 
     it "does not log cursor movement ... special output coming from docker builds" do
-      assert subject.execute("ruby -e 'puts \"Hello\\r\e[1B\\nWorld\\n\"'")
-      output.string.must_equal "Hello\rWorld\r\n"
+      assert subject.execute("ruby -e 'puts \"Hello\\r\e[1B\\nWorld\\n\e[1K\"'")
+      output.string.must_equal "Hello\rWorld\r\n\r\n"
     end
 
     describe "with script-executor" do